A note on the existence of extension operators for Sobolev spaces on periodic domains
Martin Höpker, Michael C. Böhm · Comptes Rendus Mathématique · 2014
In this note, we prove the existence of a family of extension operators for Sobolev spaces defined on ε -periodic domains. The norms of the operators are shown to be independent of ε . This extension theorem is relevant in the theory of homogenization for PDE's under flux boundary conditions.